In the mornings, when Delhi residents walk to boost their health breathing 'fresh' air, they are actually inhaling killer benzene and carbon monoxide that can fatally affect their heart, lungs, respiratory tracts, brain, bones and blood cells.

The story is deadly even in the evenings, with pollutants lurking all over, silently. It's especially bad for those living in and around Vasant Vihar, IGI Airport, Mahipalpur, Mandir Marg, Civil Lines, Punjabi Bagh and Anand Vihar, where the air is particularly toxic, experts from Delhi government's Centre of Occupational and Environmental Health (COEH) confirmed in a new report.

They attribute the high toxicity to the heavy traffic, especially of trucks, as well as benzene vapour from the petrol pumps. According to the experts, air in these areas of the Capital is so polluted that individuals with a breathing condition are vulnerable to a sudden asthma attack.

Delhi's endemic traffic problem and the
resultant toxic emissions have taken a heavy toll on its environment

Senior citizens, children and pregnant women are possibly the most vulnerable, with chances of developing respiratory disorders. Experts caution that these groups of people shouldn't even get out of their homes after 8pm in and around these areas, as pollution level increases due to freight movement around that time.

"The city is under threat and the worst part is that since we don't see the enemy, we tend to take it lightly. But, these poisonous particles are there in the air we breathe. If we don't fix it, the air will kill us. If it continues to be like this, by 2050 Delhi will be the worst victim of air pollution," T.K. Joshi, Director-Projects, COEH, told Mail Today.

Crude truth

Benzene is a component of crude oil and petrol that can be harmful even at trace levels. But the quantity of benzene is 10 times higher than the prescribed level in areas like Vasant Vihar, IGI Airport, Mahipalpur, Mandir Marg and Civil Lines.

While the standard level of benzene is supposed to be 5 μg/m3 (microgram per cubic metre), it has risen to 50 μg/m3 in these areas of the Capital, COEH experts say.

In areas around Punjabi Bagh and Anand Vihar, high levels of carbon monoxide have been detected, COEH said. A high level of carbon monoxide has also been detected at the IGI Airport where the level is Particulate Matter (PM) 2.5, with the pollution level scoring 300 on the air quality index of 1-500.

According to a recent analysis by the COEH, benzene levels are higher when the temperature is lower. And since majority these flagged areas in Delhi get colder than others parts of the Capital, the killer effect is enhanced in these areas.

The COEH also monitored Delhi Pollution Control Committee's data and found that benzene rises after sunset and peaks early morning.

"Benzene is extremely lethal and gets mixed with blood while breathing. From there on, it attacks the heart, lungs, respiratory system, nervous system and even the brain. For people who have a weak immune system, the risk is far greater," Joshi said.

At risk

Joshi revealed that a number of short-term diseases like asthma, bronchitis and other respiratory disorders, and longterm illnesses like leukemia, bone disorders like osteoporosis, the Alzheimer's, diabetes and the Parkinson's are several deadly possibilities, if people continue to inhale the polluted air.

"High carbon monoxide levels can affect those with cardiac ischemic disease, as the heart is deprived of adequate oxygen. Those with cardiovascular disease can be vulnerable to strokes," Joshi said.

So what's behind the high level of pollutants in these areas? Experts say heavy traffic on the Ring Road and Outer Ring Road, and the diesel emissions from trucks that don't go through any fuel-emission regulations, are the primary causes for polluting Capital's air.

In the last couple of years, sale of diesel-run vehicles has gone up from 18 per cent to 62 per cent, and consequently the level of carbon monoxide in the air has got increased.

"The trucks that carry diesel are the worst offenders, besides the diesel-run vehicles that stop at traffic signals and release carbon monoxide through their exhaust pipes," a Delhi Pollution Control Committee (DPCC) official said.

Apart from vehicle exhausts, evaporation from petrol stations can shoot up the benzene levels. That makes people within halfa- kilometre radius of the petrol stations vulnerable to all the diseases.

"The conventional idea is that pollution due to heavy traffic is the main cause of the diseases. But it is no longer as lethal as the petrol pumps in the city have become. The evaporative emissions at these pumps release the maximum amount of benzene in the atmosphere and none of the pumps have a mechanism called the Vapour Recovery System (VRS) like the ones in the western countries. If we have to survive in a healthy atmosphere, VRS have to be installed immediately," said Anumita Roy Chowdhury, head of air pollution and clean transportation programme, at the Centre for Science and Environment.